Some do when burned
Thermal energy.
No.
it is used to produce energy
Yes
the bio gas that the algae produce is the energy source.
Natural gas (or methane) releases energy only when it is burnt.
A gas stove releases thermal energy when natural gas is burned in the presence of oxygen to produce heat.
a lot
Oxygen is requried for respiration (your cells making 'energy'.)
When particles in a solid, liquid, or gas vibrate, they can produce heat. This vibration is a form of kinetic energy that can lead to an increase in temperature.
If there is a source of activation energy, or in the presence of an active catalyst, these elements will react to produce water.
Fracking itself does not produce energy. It is a method used to extract oil and gas from underground rock formations such as shale. The energy produced from fracking comes from the oil and natural gas that is extracted through this process.